Facile Fabrication of Highly Crystallized, Air‐Stable, and Flexible Perovskite Micromesh Film Photodetector

Abstract Perovskite materials such as organic‐inorganic MAPbX₃ (X = Cl, I, Br) have attracted broad interests in photoelectric applications, such as image sensors and photovoltaics. Here, a facile and general approach, called soft‐print solvent‐assisted evaporation crystallization (SSEC) is reported, for fabrication of highly crystallized, air‐stable, and flexible perovskite micromesh films, including organic–inorganic (MAPbX₃) and inorganic (CsPbX₃) perovskite. Scanning and transmission electron microscopy (SEM/TEM) characterization reveals their high crystallinity without obvious grain boundaries. The photodetectors constructed based on MAPbI₃ micromesh films exhibit a typical responsivity of ≈352 A W⁻¹ and detectivity of ≈5.7 × 10¹³ Jones (at 650 nm in wavelength). The MAPbI₃ micromesh film also shows good mechanical stability when bended at different bending radius, and after 800 bending cycles, they still exhibit highly reproducible photocurrent and on/off switching ratios. Furthermore, they are also air‐stable that they can survive for >20 days in high humid environments (65–75%) with <10% reduction in photocurrent. This work provides a facile and scalable approach for fabrication of highly crystallized, stable, and flexible perovskite micromesh films for a variety of optoelectronic applications with improved performance and durability.